Compared to the P5Q Pro, the P5Q Deluxe should be slightly more stable (better cooling and voltage regulation) and it has features like 2 Ethernet ports, more PCI Express slots, Express Gate SSD (I use it whenever I need to quickly access the Internet and I don't want to boot an OS, but I didn't buy it for that reason). What's not so nice is access to SATA ports once the motherboard is installed and you need to add more devices. It's not as bad as the Biostar Tpower I45, but not much better.

Another motherboard that you should certainly consider is the Gigabyte GA-EP45-UD3P which has a better layout than the P5Q Deluxe and is almost as good, but less expensive. The Asus P5Q Deluxe onboard sound is a bit better.